document.write( "Question 300563: Find the dimensions of a rectangular lawn whose perimeter is 100 feet and whose area is 600 square feet.\r
\n" ); document.write( "\n" ); document.write( "--They want me to use the quadratic formula, but I don't know how to set the equation up. That's all I'm having trouble with. I know how to use the quadratic formula fairly well. Can you please help me?\r
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Algebra.Com's Answer #215647 by nerdybill(7384)\"\" \"About 
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Find the dimensions of a rectangular lawn whose perimeter is 100 feet and whose area is 600 square feet.
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\n" ); document.write( "Let x = length
\n" ); document.write( "and y = width
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\n" ); document.write( "2(x+y) = 100 (equation 1)
\n" ); document.write( "xy = 600 (equation 2)
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\n" ); document.write( "Solve equation 2 for y:
\n" ); document.write( "xy = 600
\n" ); document.write( "y = 600/x
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\n" ); document.write( "Substitute the above into equation 1 and solve for x:
\n" ); document.write( "2(x+y) = 100
\n" ); document.write( "2(x+600/x) = 100
\n" ); document.write( "x+600/x = 50
\n" ); document.write( "x^2+600 = 50x
\n" ); document.write( "x^2-50x+600 = 0
\n" ); document.write( "(x-20)(x-30) = 0
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\n" ); document.write( "x = {20,30}
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\n" ); document.write( "Dimensions are 20 feet by 30 feet
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